SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0559369e6303ab2d3665a7e2e12920dcda9bf16a1170a7e16e24a093aa8c3ee9' 
  AND token = '2I/XdRZNgZ/9lMA1tUCGQE933RPFnPWBengSlvkSHQ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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