SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f42afcb3399c4b4391e943ace9ffd2dd0e312eab567c63bb3ce4b9392382e48' 
  AND token = 'n6PjmNrrTUxuc8OeIAAbFq5qjsntFKsuvaaPSypA1hg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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