SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0385f5a59b6f048c123a784c7c0147ca5ace641f232683102dbd386d236b6c1c' 
  AND token = 'Iqf3HMsBZ+LxBMfZIDXMJcTI8PsdjWeX/xxVN4wLBfw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}