SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9114c03e20910848f2cc32115bba5e72c89e0fdf9ba4a8be55f52c6499325db0' 
  AND token = 'xMNCSWB5xXPQ3YOFebIB77BQXJMIqivn+YSBlYGkbcw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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