SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c851d2a916ea13fc77562e33d82cd8ac9f49d5000083d160a33a5b3d726640f' 
  AND token = 'Mnjje2tbWGstlsyYe6ArScL6HwsDmkLd7Ldp1UEzDsI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00059

JSON explain

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