SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad088305b624b6f9620166863ec879fdc2699b0d83d99789195c631844f1e634' 
  AND token = 'k4izo+gZYeo6ShEyOVAzNLRGgdV2CYQlzYk7BxUlXK4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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