SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a65d73b8168640417ed26b2a7d88360ca2be9daaf5fd28b8a7312bf339f2adf9' 
  AND token = 'gXKbrIn4vyjsKsePQcPdbt08O83LASqV/7Yj3MWieXw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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