SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b69a7230e0bb8be995d8f264f674d4d3225a25b0763786b049555e5fb34e2a0e' 
  AND token = 'jevxBDisnYl1qV+ftYTpflhgqNXqhP8DnMB0OaSovVQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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