SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6890170c87bb2da09f07fd1fb1436881b7ab5cb4cb868088b1acea60ebb087ac' 
  AND token = 'dy1AcdPM93qffAb/YUh93+GWIZgyZiOZ7+bGwpqSd38=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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