SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '57e0cd25001d491fac193089be3dba9eb87d321d3e56eaf98835ee1e5bd09d5b' 
  AND token = 'IOVvd8bhk34wmbVCfSDhCAUnaM2OjlDndgYWuExWW5w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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