SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ecaadcf89da8cacc5e31e94c5229278ac7a9eb3d0599699dc174b044f8235aa8' 
  AND token = 'SSMAt8h4tb+1RVyNFmdOCaYKeClZOsP80WjLfNZjXmg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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