SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd08f6dd2f2f3b1b2841a8025bfe2aa0199f9aa90379c59641207ea2b097c10cc' 
  AND token = 'FuO4rDRxcuBEC0gJwk1HVbPTDpkfppkkl1cOVb5ZqKc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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