SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9397b8ab2e654fc33ca2ab393ef81f22f1e9f794e34f4296b9c5254fa1886d7f' 
  AND token = '/aSqvoulJapA95lKwMcY0BTV2CSgRhip+nAjge/+92w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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