SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b347302b071b34f2e53df667baf181b0a7ce499b5ad27c57951951b61fe258a' 
  AND token = 'KjyCzI1T1ThOie28WgXYlkDLeFMnIkRG632JdkGt0qc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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