SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e75eb8b2a343ffd8a8b8d3f5dec612ea1babd989f4b828075a51dd68e0519b95' 
  AND token = 'adJEKNQ0irp3NCBObKkNqR6Man4Uwsi52gt6Qu+pH5s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}