SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b8fc96e7c2cc53e9f03d20e30be4ee0c6699fa6517111b4dbc2b20cc8103723' 
  AND token = 'DY5WpqFzFZBtzyZsXQlJlHEKbIZtNgMN/pMMg8UPmSs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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