SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0283c5b811fec2b59b82ad2f8b4e31a6336a6d4f8bd675b69c2f03aadc14b74c' 
  AND token = 'gNQmZhCqHV207qKx3uyhIbTJwTh81D+smjRqpJPEFGA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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