SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e694ad882b04909cd8f8b6104504322e8bb13cb4cd8693012eac05499702ea0f' 
  AND token = '/VOb0+MzPKMI6Wotwk95bFDRbJMNHNSl9zjuAcqnH7s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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