SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '362f5357178634dd25aa0e2041dd425b6ff3bf8c960cfb4e753137a8da1633f1' 
  AND token = '4ruEVXU0YzkrDgiP5aHCN9nSh63eBWL/7o6BNk32eyM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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