SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47bfe34d70d5ec807af3b27d4b03ae4e1ecba2eb803cf8f4de20888cda08dd69' 
  AND token = '5c8EpQO1ZdK4Q8hvmS6UarBhh4axuUBM6AciJbQRB0Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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