SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc67973bf4545da04f4da89d39d9e5ae9e23c3edd3769697f5a5a9b4326b3e95' 
  AND token = 'hVHKqHajIL/zHqzjqnuzIsVbUoIzqBJR+IksMp/KtYA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00012

JSON explain

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