SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb633c32cb149d7e1a98fdb70236b47f3aa93512cbceb8f4994f4171ddf80235' 
  AND token = 'Mdh21miFYJBq+m+z+WkOFCfNXAmprhusHAvIydoTZZ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}