SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8b6aa92018c2cec33c060578b856c876ee0edfaed0d3872af632ef8e08a307b' 
  AND token = 'XdEzG+uoBpkqbosbgKpln8pbAyX6BWG/nW5YsvzxuDI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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