SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46271952be76a2a5b94d26c456c07d33f1220f9027a79f7c619a1965e9136e74' 
  AND token = 'ExB+Osvau9+5kX40cV4GP/b3mGQP93T/z952HCLkYZI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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