SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c4928b2a76e0adef277d36b590dd6b610a9a141443d7a10189d9f212256fdac' 
  AND token = 'GcpgKQat8SRPR/wODZENqLw/2GlSkCYiDfc0WeBwLbg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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