SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30a738898edcad7f2254c654e3d73bfd814dd094cede7156342631be3c28f64a' 
  AND token = 'tDPdzsFBgPT4eI4AYd2tHHhkvJJgPXaDeGiSm78F0X8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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