SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '529acff53cb9bb6b521b47c6998a68e2aeea28ee203aec108fe84d0a1b20f29c' 
  AND token = 'lh+MNOTCLGIs5FW8mDbUyRE+MF5cjSf9nrKB9J7FFt8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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