SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8cbe7b4c8626263ded582e558e13287a360aa42c602f36b62fc3ad5da49afe05' 
  AND token = 'UD6oxQJK2tJaNJlIJSQj3m7Ghl7pMzaOEr4LF9SCRiM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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