SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '897004ea473aacb280d77131911072ed19cdd3fa408de5d93cfcab996cbf6519' 
  AND token = 'takgR8e7aALvq7GiiQtc8Aoukxw06/4NH6BAwuPHLW4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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