SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c85ad2050d0b5489065cb3326c409573fb10f61036d9fdae101d50e05c7b067' 
  AND token = 'PJmQRbac+7+Fi1EWGGjT7mt8GxqTLQV2orBJ9NiS3Zc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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