SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5055a58a4eed91da2aa9c64b534033026f3b976453ec2cbbd0786ecff82f3d07' 
  AND token = 'CkDgaS9blROs361ZMsUsu8VfEa+1Vlkj5yCqAa0P5E8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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