SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34f4d7bcbaa14ddb0b68507c760874d07de484114a4c87de802d4d8800dec134' 
  AND token = 'uAal4VAiBkUr7jRhYULw4owBB0R7JEHh/H0HiCcJkzU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}