SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41cfb276c801695ddb0774c75cc2a913e148e25f97ec578e2899bd2e40b530d3' 
  AND token = 'J9LEJygHwr3mDODfTL5cPzcJ7lokFMSqfuOoZC1pm44=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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