SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f70f99b14bf4d9d395720aaeb54540c5481117c4c0ef38abde660f8531bf349' 
  AND token = 'AVu7vJG5xozBtc+sTNFShlrnJs1dxozKJDtTlQGbpJU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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