SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11eff648b2e827ecc6a6d3e28b56dff4c78ef7a04f39bf1989827b621101b599' 
  AND token = 'Jdrm/sijlTw44GB9lb3ss2zr7eKve5Z4/B/YS+2dajw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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