SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ed07a16763230ce0cc2001008109bc416100affb662efdeff694b72c4aab43f' 
  AND token = 'rSlDnswVvyMECRLPitAsfWKdvtpnUEeL+NymMrWrQko=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}