SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'edbfc8a53b4542cbc751222813d8910713c365af6be0fe38906fc5005a9663e9' 
  AND token = 'fUTHPNJ1Ep6T7BmRnNKhKGJagdk6FRP25+poFN08FS0=' 
  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"
    }
  }
}