SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66aeaa1cf016503d9b75279e4352a185d3671fc584824109d93a511c40bd886b' 
  AND token = 'ePt5IOvjNN1WmnSto0IonpHFBJozwQ5LNlkAWdurO6Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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