SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ad5b3a09c7bd0ab539ede76bfc4ee62fbf77e4891cd47b4d7b2b04a694c24b6' 
  AND token = 'BCnVy4qsjW0iiP9jljxYAQCb6D2Qhxns9WWP318LIVw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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