SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c04a69a5ee53fe0bb4fecfb585dc58bfd41b58dd9c875b72d6b4697500181bd1' 
  AND token = 'MNW0Q4jYgt7IjV+6F2OmSL2OhyoPtLURafRmer+4gYk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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