SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '38db65b8522f7867f5935813c3e7d5c82015b974d8c82ed2b4184b622ec2d7ae' 
  AND token = 'caQI9DRWyGYMg/X7CWo9waMTMPt9pExyKslJBrkE11I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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