SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b97f785154eb485f65f4bf32ae242ca8f0d55b33426df869cea2696c0ed8be1' 
  AND token = 'kOji0IkjksjH25BsqTpFNLGZxGxGQHXP0PSDpW5pgBA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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