SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d7d0de17f3557042ad8626f740ae8afe4617a597a73508d421a7e6c6e48988a' 
  AND token = 'UVJRo9EL9bD0eZ30Hk/kTTFbWL29ss8S8HbSxgHEb64=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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