SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69b1059b8219447426fdb083825c934afb87a8097c8dd06f7402dded284f3d5e' 
  AND token = 'F/54zNPMG9mLpZouKn4HYk32pJATyVh2sByOhK4Jv4o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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