SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8f4dc9c33f219bb75b50919b07d4eeb27708874baff64182ec1afbf2367f708' 
  AND token = 'GIfn03ifzJzXxBhoj/qkFbrEfjw3zNxlZhjJE+gZ3Gg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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