SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '445a2522ff545fc09b8f18cec06318affd4889cc5f38166f9feaffda559ba37d' 
  AND token = 'jBY1qgR5rPEL7m/rrptMIytBmnbYJk65wNDJRoVe/0Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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