SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '416cf3403e57420470a577dceb3fc4abc1dc6096d84d4cb71422a2563f72d1a6' 
  AND token = 'jPVHXms7XMeqf0llaREhcxzNQuSWdH1efY52JQWj1og=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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