SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8604e833059a9ae15ea1ce4ccd7897930fa2a16baf487415515bcdccfde68efe' 
  AND token = 'OqM+bZmqvHjtnaE3jB3o20/mZA3DXcvalwCn9ZzwH+I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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