SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '163a0026aadd3fb6079e08b9a9910b06da293bca25d604804bea8a9a11792ab6' 
  AND token = 'WrcSyad94aZxh1DXSvh7zvl4iER7XjYqIK2DNTNOSj8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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