SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '379f839c83703e0afd6bfba4ce0ccc07e9127c243b07403b9b3035b44649a5a5' 
  AND token = 'faw/wFrPsyyYCaBDcRHCFbASi4XMJTdZJsKKkFAGZwo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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