SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f47afd9d1b3bb24701051029a9b2e5203d2efd07e298cc70ef7949b5f968dc2' 
  AND token = '690prb6lmDiGAYY+/F3q9QNJvOGHbxqCBpbiMlEHm6w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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