SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '152904a1595ea3c99e3f81eddc3930875f0587b067dd61432e4a48fc8868bdb6' 
  AND token = 'jsqtwxSL1gIvJBm2eCY6PpYzpJAfBSB6wFsVCaYWQjM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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