SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7a374af2d6a9702ec7229565e1604a605e1d44ad87a5e9fb4f40cc0894137a1' 
  AND token = 'n+IQ8+TVRud0n9QlGupDzg3JKpYO3sAnvZV4RYOXR8k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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