SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c1b244232c47bd455da6e2e452ed904731849e56f3b2a1f2987ed1ab0fab3183' 
  AND token = 'hWde5htVNjHzHVHgBL2kp/hTuYy98kZyPRAZ6/myBno=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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