SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7434d197e1df4ae73d892a1e9875f31cbae7550ea79c226c288b134438043ffb' 
  AND token = 'RWvvBHj7loM9caPvDHU0l6GHboyUq71CyKDIQ69ZMrU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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