SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ed77035a06262a23ee44a4762c2a956534dd219b2516f7b52671e4599b1d868' 
  AND token = 'hvTZl5kw/MGJQ3thkeccBdnjKvqCAJjC13VY8H+xhvs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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