SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8978bdcd04e260a36516aa3dd91bdd2b71406313fcae891deeb2886a54cb5c11' 
  AND token = 'kfMd80jvDQMzUxnTDb1f3qpJ4vO2LfL6PagcmEsgDes=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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