SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '107add77a669d9cd00f78d0e15426f96b6820dc39cf21df3cdda5201edded7ce' 
  AND token = 'aWEqvBmlOR9MuIB8rYUcQ4ybCwvnzTZmMDDIMslf5vg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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