SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6bd2e65a862c58fc2723efa1a4e48d963e124fd3398a14e61d07395cc928e935' 
  AND token = 'V3drZ2y7INg+6lGpQP1QYj8xfKBym+nu9tVpuzfIOyM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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