SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14e5c9000b08121eaca8a1f48b33b0ff1e7725692ecfbb7599472aff083e4058' 
  AND token = '+h+vjTQhpj8Y2ZtY64A9TOCUs49Aaz/jokQdCDKZuns=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00073

JSON explain

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