SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a7fc66b9ef3f5ea9db387bc505f37b60da1711703bb9c56bdc6a1da42ea17aa' 
  AND token = '+6jrbhxi7kjIFxeubuTZb1MNBoKscvnAuB5KQmswhYQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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