SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5641a271e3e8fe6d81ccfe0466aed162fdb4f1f731669ee03e2407eb3172f259' 
  AND token = 'tK+BDx3V/qEzZjZAYrqOgttGEOeY0qzjjwW58+Jg0aI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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