SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '21aab6ad245959d72827e5848cd45a8f62e02e6d869cef32a25e86b60dd9a4de' 
  AND token = 'KeQjviqG98vPtW/+MnhgaQ41qTbkBaqw0TX6soJ64k8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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