SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dffd27a937f3b79ca3c13cedc19a5d936d985120a804e59c43c6edf51e8f4007' 
  AND token = 'Z59+OX5KBEXvjyl7mp+PhPDKGEAfTWK68eF2iAr1SO0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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