SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2ab83f82ba14eb74ae652c1456341c095577e91a5ae85e74f4c78bbbcaec773' 
  AND token = 'rc1PM5VM7fvrEbslmFXM0jDjk4saLbIuuaF44MpHWsk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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