SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66668511ea9a6b2c3c7034574a61f94d533167767115275881b3aba7504f2913' 
  AND token = 'bjd1ZmAg52G0li6xBjP+2wCIoFxNEYNNBb9sC0AJNFk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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