SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d778e0f9ec2134ef0b52cd93bd1215e14f0fe2222bbcf146762fb62f526050b' 
  AND token = 'zeYaAg1QnDRv+r26IewINj+YolFQmVj5wZqgsXxpP2A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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