SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'ebc4f05f4de1fa1c93de007733ea43e41eecef1d5f750d609c13783f867da86e' 
  AND token = 'gtwKfDwrlOkOCJDBLVaYI0I2c5B12yxP78iScb6KhoQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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