SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc0928e32a41edbc61b30168c84c979ded96ce61c3015e6e277715fe41626741' 
  AND token = '/GiGSxWgo4HrE+1kcg37gmYyLuZqsDK6etsSGqiJazM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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