SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30bc5753669f0e3c2a46b493a0624575e43cf8661388cd8f448bc1846326cbf9' 
  AND token = '/ftQObIUtWXxDHixTrtalZuiYmK8wD5ojpz5uHXUoB8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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