SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85566c2281f88fc5f10a6f932400d83f107274fa5f1c32259659627f82211c53' 
  AND token = 'BFloeHlyFFeSU3kZUQdxiNyi6sYAYuPO6iltd9D2Cs0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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