SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2ecd71f3e5c9a1883fd3fb00fa733d6236d4f03cedf5dc42316ca1bb19ac5c5' 
  AND token = '0onfFzMpSn9y2NDSJRtcjcjjK6B/Ag7BNpb1b3IFcxM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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